Agitator structure for cleaning devices



April 10, 1956 G. E. KAUFMAN 2,740,985

AGITATOR STRUCTURE FOR CLEANING DEVICES Filed Nov. 10, 1949 2 Sheets-Sheet l TIBET Fly. 1

INVENTOR. George E [(a ufmcm BY 6 ATTORNEY.

Aprili 10, 1956 G. E. KAUFMAN 2,74@,985

AGITATOR STRUCTURE FOR CLEANING DEVICES Filed Nov. 10, 1949 2 Sheets-Sheet 2 YIIII/II/ m INVENTOR. y 4 Georyefl Kaufman atent @fiice 2,740,985 Patented Apr. 10, 1956 AGITATOR STRUCTURE FOR CLEANING DEVICES George E. Kaufman, Canton, Ohio, assignor to The Hoover Company, North Canton, Ohio, a corporation of Ohio Application November 10, 1949, Serial No. 126,545

7 Claims. (Cl. 15-383) The present invention relates to cleaning devices and in particular to an improved sweeping and agitating brush structure particularly adaptable for use with suction cleaning devices.

Most effective carpet cleaning with suction cleaning devices is accomplished by mounting a brush roll in the suction nozzle having rigid, agitator bars and flexible brush bristles projecting a small distance from the surface thereof to contact a carpet undergoing cleaning. The degree of radial projection of the brush bristles beyond the surface of the roll is small but the bristle length must be much larger than this to provide a degree of flexibility in the bristles which will prevent the brush from abrading, that is, wearing a carpet undergoing cleaning. The rotary member is customarily driven at a high speed upon antifriction bearing supports at opposite ends thereof. The anti-friction bearings extend into opposite ends of the roll and the clearance between the surface of the roll and the bearing structure is less than the amount by which the bristles of the brush should extend into the roll to have the desired degree of flexibility. The foregoing factors have limited prior practice to the provision of brushes which do not extend over the bearing structure thus achieving the desired flexibility in the brush but leaving a space at each end of the roll bare of brushing elements.

It is a principal object of my invention to provide a brush roll for suction cleaning devices having brushes extending the full length of the roll which have the characteristics necessary to avoid carpet wear due to the effect of the brush.

It is a further object of my invention to provide a brush roll for use in suction cleaner nozzles having long brush bristles in those portions of the roll which lie in the central portion of the nozzle where the carpet dis placement from its supporting surface by the suction air stream is greatest and shorter brush bristles at the ends of the brush roll overlying the bearings where the carpet displacement is a minimum.

It is a further object of my invention to provide a suction cleaning apparatus having a brush and agitator roll therein in which the stiffness of the bristles progressively decreases toward the center of the nozzle at which point the carpet elevation under the influence of the suction is the greatest.

Other objects and advantages of the invention will be come apparent as the description proceeds when taken in connection with the accompanying drawing in which:

Figure l is a front elevational view of a suction cleaning device with a portion of the nozzle cut away to illustrate the brush roll and its relation to a carpet lifted under the action of the suction air stream;

Figure 2 is a partial sectional plane view of the agitator device drawn on an enlarged scale;

Figure 3 is a sectional view taken substantially on the line 3-3 of Figure 2; and

Figure 4 is a view similar to Figure 2 illustrating a modified form of the invention.

Referring now to Figure 1 there is illustrated a suction cleaning device illustrated generally by the reference character 1 which comprises the usual electric motor and suction air fan driven thereby. In accordance with usual construction the motor also drives a belt 2 which drives a brushing and agitating roll 3 positioned within the suction air cleaning nozzle 4. A dirt laden air discharge duct 5 for the fan is provided for connection to a conventional filtering device.

The brush and agitating roll 3 is mounted upon a shaft 7 in a manner to be described more fully hereinafter. The shaft 7 is suitably supported in the nozzle 4 upon a nozzle lip defining plate 10 which is attached to the cleaning structure in any desired manner.

Referring now particularly to Figure 2, the brush roll structure 3 comprises a generally cylindrical shell 12 having a reduced central portion defining a pulley section 13 for receiving a driving belt. The ends of the shell are secured, by welding for example, to end disks 14 having bearing cups 15 formed integrally therewith and extending inwardly of the shell 12. Ball bearings 16 are received within the bearing cups 15 and rotatably mount the shell structure 12-14 upon the shaft 7. A hearing retainer nut 17 engages a threaded part of the shaft 7 to secure the bearing on the shaft. A flanged guard 18 is threaded on to the threaded portion of the shaft 7 and overlies the juncture point of the shell 12 with the disk 14- to shield the bearing from dirt, threads and the like.

Rigid agitator bars 20 are mounted upon a surface of the shell 12 and are preferably curved to form a section of a long pitch helix. The bars 20 extend between the pulley section 13 and the flanges of the thread guards 18.

The shell 12 is provided with longitudinal slots 21 extending from opposite sides of the pulley 13 to the ends thereof. The portions of the shell defining the edges of the slot 21 are bent to form inwardly turned flanges 22. A brush back 2 having projecting side wings is seated within the slot 21 with the wings 25 resting upon the flanges 22 all being within the diameter of the shell 12. The brush back 24 is secured by means of bolts 26, which extend through suitable openings in the side wings 25 and flanges 22 and engage spring nuts 27 to lock the parts in assembled relation. The brush back 24 carries bristles 28 which project radially of the shell 12 to engage a carpet undergoing cleaning.

Referring to Figure 2, the outer end of the brush back 24 is stepped as indicated at 30 to clear the bearing cup 15. The portion of the brush back positioned inwardly of the cup 15 penetrates the interior of the shell 12 a distance exceeding the distance between the outer surface of the cup 15 and the surface of the shell 12. Since all the bristles 28 project a uniform distance from the shell 12, the bristles on the step 30 are comparatively short and stiff and the remaining bristles are long and flexible. The long bristles 28 have suflicient flexibility to clean without producing carpet wear. The short bristles 28 at the ends of the roll 3 over the bearings are comparatively stiff but are tolerable at this point for reasons to appear. The side wings 25 on the brush back 24 are preferably continuous but extend from the step portion 30 of the back close to the underside thereof Whereas they project from the top portion of the main section of the brush back as shown in Figure 3.

Referring now to Figure 1 the apparatus is shown in operating condition, that is, the motor is energized to create a low pressure area within the nozzle 4 which results in lifting the carpet 35 above the floor surface 36. The action of the suction air lifts the center of the carpet well into the nozzle mouth but the carpet underlying the ends of the nozzle structure is lifted a comparatively small amount due to the less effective suction at this point, the drag of carpet outside the nozzle and the effect of the front supporting wheels, not shown, which conventionally are positioned immediately behind the outer ends of the nozzle. The low elevation of the carpet underlying the ends of the nozzle prevents the stiff bristles at the end of the agitator structure from penetrating deeply into the carpet pile and undue wear is avoided. The long bristles inwardly of the ends of the agitator fiex in operation so that they do not dig deeply into the carpet pile and do not cause undue carpet wear. By reason of the foregoing construction the advantages of brush bristles extending to the very end of the agitator are secured, combined with the desired flexibility to be obtained by long bristles in those portions of the agitator in which the carpet is raised to a comparatively high level with respect thereto.

Referring now to Figure 4 there is illustrated a modified form of the invention. The apparatus illustrated in Figure 4 is identical with that illustrated and described in connection with Figures 1 to 3 in all particulars except with respect to the specific construction of the brush. Those parts of the apparatus illustrated in Figure 4 which are identical with parts of the apparatus of Figures 1 to 3 are given the same reference characters as their corresponding parts distinguished by the addition of a prime. In this form of the invention the brush back 40 is inclined or in the form of individual steps so that each bristle tuft 41 is slightly longer than its neighbor to the right, as viewed in Figure 4, and is slightly shorter than its neighbor to the left. The inclination of the brush back 40 is such that the bristle tufts at the end of the agitator are short enough to clear the bearing cup 15 and the bristle tufts inwardly of the bearing cup are long enough to possess the degree of flexibility desired to prevent objectionable carpet wear. As will be seen from Figure l, the suction in the nozzle 4 lifts the carpet along a curve having its greatest displacement from the floor surface at the center of the nozzle. The brush structure of Figure 4 is characterized by bristle tufts of varying length so that the flexibility of each bristle tuft is proportioned to the displacement of that portion of the carpet which it individually contacts in the use of the device. The longest and most flexible bristles at the center of the agitator structure contact the portion of the carpet which is displaced the maximum amount and the shortest and stiifcst bristles at the end of the agitator engage those portions of the carpet which are lifted the least resulting in a substantially uniform cleaning effect over the full length of the brush.

The present invention provides an agitator and brush roll structure particularly adapted for use with suction cleaning devices in which the bristle structure extends to the ends of the brush roll over the internal supporting bearing therefor to secure maximum cleaning effectiveness while insuring that the brush bristles will, at all points along the length of the brush strip, be long enough to have flexibility such that their penetration into the carpet nap will not produce undesirable wear thereupon.

While I have illustrated and described the invention in considerable detail, it is to be understood that various changes may be made in the arrangement, proportion and construction of parts without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. In a suction cleaner, an elongated suction nozzle, a brush roll rotatably mounted in said nozzle and extending substantially the full length thereof, said roll being provided with strip means supporting brush bristles projecting a uniform distance outwardly of said roll, the strip brush bristles adjacent the ends of said nozzle being stiffer than the strip bristles adjacent the center of said nozzle whereby the strip bristles adjacent the center of the nozzle offer less resistance to a fixed displacement of the outer ends thereof circumferentially of the brush roll than the strip bristles adjacent the ends of the roll and a surface covering lifted into engagement with said brush roll by suction applied to said nozzle is acted upon by relatively stiff brush bristles adjacent the ends of said nozzle and by relatively flexible brush bristles adjacent the center of said nozzle.

2. A brush roll for suction cleaning apparatus comprising a cylindrical body member, a bearing structure in each end of said cylindrical body member, a brush structure including a back having brush bristles projecting therefrom, said back including a stepped portion at one end having shorter bristles than the remaining portion thereof and means mounting said brush in said body member with said bristles projecting a uniform distance radially outwardly of said body member and the stepped portion of said back overlying said bearing structure.

3. A brush roll for suction cleaning apparatus comprising a cylindrical body member, a bearing structure within each end of said cylindrical body member supporting the same for rotational movement, a brush including a back and bristles projecting from said back, the bristles adjacent one end portion of said back projecting from said back a lesser distance than the bristles removed from said one end portion, and means mounting said back in said body member with said one end portion of said back overlying one of said bearing structures and said bristles projecting a uniform amount radially outwardly of said body member and terminating in end portions spaced equidistantly from the axis of said body member.

4. In a suction cleaner, an elongated suction nozzle, a brush roll rotatably mounted in and extending substantially the full length of said nozzle, bristle supporting strip means in said roll, brush bristles secured to said bristle supporting strip means and extending outwardly from said roll, said bristles terminating in free end portions positioned equidistantly from the axis of said roll, and said bristle supporting strip means being so positioned with respect to said roll that the distance from said supporting strip means to the free end portions of the bristles adjacent the ends of said roll is less than the distance from said supporting strip means to the free end portions of the bristles adjacent the central portion of said roll, whereby a surface covering lifted into engagement with said brush roll by suction applied to said nozzle is acted upon by bristles adjacent the center of said nozzle having a greater length than the bristles adjacent the ends of said nozzle.

5. A brush roll for suction cleaning apparatus comprising a cylindrical body having a recess in its cylindrical surface, a brush including a strip back having bristles projecting from one surface thereof, the bristles at one end portion of said strip back projecting a lesser dis tance from said strip surface than the bristles at the other end portion, and means mounting said strip back in said recess with said strip surface at said one end portion closer to said cylindrical surface than the strip surface at said other end portion to arrange the free ends of said bristles at a uniform distance outwardly from said cylindrical body surface.

6. Apparatus according to claim 5 in which said other end portion of said strip back is positioned at a lesser radial distance from the axis of said cylindrical body than said one end portion of said strip back.

7. Apparatus according to claim 5 in which the distance from the free ends of said bristles to said strip back surface progressively increases from said one end portion of said strip back to said other end portion thereof.

UNITED STATES PATENTS Watkins Feb. 24, 1903 Smith Dec. 28, 1920 Nulsen Dec. 27, 1927 Leahy Jan. 6, 1931 6 Losey Oct. 25, 1932 Wolfe Oct. 9, 1934 Glass Mar. 29, 1938 Smellie Apr. 22, 1941 Finkelstein May 9, 1950 FOREIGN PATENTS Sweden Dec. 29, 1904 France July 29, 1927 

